The leading names in the current author/editor could be compared with the previous bibliography entry's author/editor using internal lists from etoolbox. These lists can be built up with \indexnames.
Some counters and tracking of the last entry's gender field help ensure that the names are properly delimited and use of the appropriate idem bibliography string.
For simplicity I've assumed no truncation of author/editor. It is possible to permit truncation. However the resulting style would be rather ambiguous; recurrent andothers read identically, but could refer to different authors/editors.
The solution could definitely be made more efficient, probably with the use of a routine that drops a specified number of elements from the end of a given list. It could also make smarter use of information available in the gender field, either from entries before just the last one or from the current entry.
\documentclass{scrartcl}
\usepackage[T1]{fontenc}
\usepackage[american]{babel}
\usepackage{csquotes}
\usepackage[style=authortitle,% Based on this style
maxbibnames=99,% Solution assumes no truncation
backend=biber,% Needed if using hash field
sorting=nyt,
abbreviate=false]{biblatex}
\newcounter{bbx:idemcount}
\newcounter{bbx:namecount}
\newbibmacro*{bbx:printlist}[1]{%
\global\csundef{bbx:namelist}%
\global\csundef{bbx:checklist}%
\setcounter{bbx:namecount}{0}%
\indexnames[bbx:checklist]{#1}%
\ifcsequal{bbx:checklist}{bbx:idemlist}
{\ifnumequal{\value{bbx:namecount}-\value{bbx:idemcount}}{1}
{\let\finalandcomma=\empty}
{}%
\printnames[idem:first-last]{#1}}
{\printnames{#1}}}
\DeclareIndexNameFormat{bbx:checklist}{%
\addtocounter{bbx:namecount}{1}%
\listcsxadd{bbx:namelist}{\thefield{hash}}% Or #4 #5 #1 might be sufficient
\ifnumgreater{\value{listcount}}{\value{bbx:idemcount}}
{}
{\listcsxadd{bbx:checklist}{\thefield{hash}}}}
% authortitle uses sortname format - i.e. last-first/first-last
% Use \biblstring \bibxlstring for long idem, irrespective of
% the abbreviate option setting
\DeclareNameFormat{idem:first-last}{%
\ifnumequal{\value{listcount}}{1}
{\ifboolexpr{ test {\ifbibxstring{idem\csuse{bbx:idemgender}}}
and test {\ifcsdef{bbx:idemgender}} }
{\bibstring[\mkbibbold]{idem\csuse{bbx:idemgender}}}
{\ifnumgreater{\value{bbx:idemcount}}{1}
{\bibstring[\mkbibbold]{idempn}}
{\bibstring[\mkbibbold]{idemsn}}}}
{\ifnumgreater{\value{listcount}}{\value{bbx:idemcount}}
{\iffirstinits
{\usebibmacro{name:first-last}{#1}{#4}{#5}{#7}}
{\usebibmacro{name:first-last}{#1}{#3}{#5}{#7}}}
{}}}
\newbibmacro*{bbx:savelist}{%
\savefieldcs{gender}{bbx:idemgender}%
\setcounter{bbx:idemcount}{\value{bbx:namecount}}%
\csxdef{bbx:idemlist}{\csuse{bbx:namelist}}}
\renewbibmacro*{author}{%
\ifboolexpr{ test {\ifuseauthor}
and not test {\ifnameundef{author}} }
{\usebibmacro{bbx:printlist}{author}%
\setunit{\addcomma\space}%
\usebibmacro{bbx:savelist}%
\usebibmacro{authorstrg}}
{\global\csundef{bbx:idemlist}%
\setcounter{bbx:idemcount}{0}}}
\renewbibmacro*{bbx:editor}[1]{%
\ifboolexpr{ test {\ifuseeditor}
and not test {\ifnameundef{editor}} }
{\usebibmacro{bbx:printlist}{editor}%
\setunit{\addcomma\space}%
\usebibmacro{bbx:savelist}%
\usebibmacro{#1}%
\clearname{editor}}
{\global\csundef{bbx:idemlist}%
\setcounter{bbx:idemcount}{0}}}
\renewbibmacro*{bbx:translator}[1]{%
\ifboolexpr{ test {\ifusetranslator}
and not test {\ifnameundef{translator}} }
{\usebibmacro{bbx:printlist}{translator}%
\setunit{\addcomma\space}%
\usebibmacro{bbx:savelist}%
\usebibmacro{#1}%
\clearname{translator}}
{\global\csundef{bbx:idemlist}%
\setcounter{bbx:idemcount}{0}}}
\usepackage{filecontents}
\begin{filecontents}{\jobname.bib}
@BOOK{book1,
author = {Buchautor, Emma-Louise},
gender = {sf},
title = {First Title},
date = {2001}}
@BOOK{book2,
author = {Buchautor, Emma-Louise},
title = {Same female author},
date = {2002}}
@BOOK{book3,
author = {Buchautor, Emma-Louise and van Helsing, Sarah},
gender = {pf},
title = {Same first author whose gender is unspecified},
date = {2003}}
@BOOK{book4,
author = {Buchautor, Emma-Louise and van Helsing, Sarah and Knuth, Donald E.},
gender = {pp},
title = {Same first and second female authors},
date = {2004}}
@BOOK{book5,
editor = {Buchautor, Emma-Louise and van Helsing, Sarah and Knuth, Donald E. and Cicero, Marcus Tullius},
gender = {pp},
title = {Same leading names of mixed genders},
date = {2005}}
@BOOK{book6,
editor = {van Helsing, Abraham},
title = {Different name},
date = {2006}}
@BOOK{book7,
author = {van Helsing, Abraham},
gender = {sm},
translator = {van Helsing, Abraham},
title = {Same male name},
date = {2007}}
@BOOK{book8,
editor = {van Helsing, Abraham and Jackson, Tom},
gender = {pm},
translator = {Cicero, Marcus Tullius},
title = {Same first male author},
date = {2008}}
@BOOK{book9,
author = {van Helsing, Abraham and Jackson, Tom},
title = {Same male names},
date = {2009}}
@BOOK{book10,
author = {van Helsing, Abraham and Jackson, Tom},
gender = {pm},
title = {Same authors of unspecified gender},
date = {2010}}
\end{filecontents}
\addbibresource{\jobname.bib}
\begin{document}
\nocite{*}
\printbibliography
\end{document}
For comparison here is the same bibliography generated with no changes to the authortitle bibliography macros:
Best Answer
The general idea is inspired by Audrey's answer to With biblatex, is it possible to replace one author of an author list by a bibnamedash or idem string?, but takes a very different approach in the end.
You can control the inserted dash with
\bibnamedash, the separator between two of those dashes is\multidashdelim, the last is separated by\finaldashdelim.If you want the dash to be able to jump over names, you can just change the line
to
you can then also remove all mentions of
bbx:goahead.MWE
We can make this a bit more safe if we use
a new macro
dash:cleanupthat can be implemented asand is used as
You will then have to change the
in
dashed:given-familyto the slightly longerAnother clean-up solution is
In any case you could want to add a
and not test \iffirstonpageto the\ifboolexprindashed:given-family.